Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755968AbZGVI1K (ORCPT ); Wed, 22 Jul 2009 04:27:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753257AbZGVI1J (ORCPT ); Wed, 22 Jul 2009 04:27:09 -0400 Received: from relay.gothnet.se ([82.193.160.251]:51449 "EHLO GOTHNET-SMTP2.gothnet.se" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753906AbZGVI1G convert rfc822-to-8bit (ORCPT ); Wed, 22 Jul 2009 04:27:06 -0400 Message-ID: <4A66CD54.6070104@shipmail.org> Date: Wed, 22 Jul 2009 10:27:00 +0200 From: =?UTF-8?B?VGhvbWFzIEhlbGxzdHLDtm0=?= Organization: VMware User-Agent: Thunderbird 1.5.0.7 (X11/20060921) MIME-Version: 1.0 To: Jerome Glisse CC: Dave Airlie , linux-kernel@vger.kernel.org, dri-devel@lists.sf.net Subject: Re: TTM page pool allocator References: <1245931298.13359.8.camel@localhost.localdomain> <4A439D7D.9030401@shipmail.org> <1248197676.2368.11.camel@localhost> In-Reply-To: <1248197676.2368.11.camel@localhost> Content-Type: text/plain; charset=UTF-8; format=flowed X-BitDefender-Scanner: Mail not scanned due to license constraints Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2242 Lines: 64 Jerome Glisse wrote: > On Thu, 2009-06-25 at 17:53 +0200, Thomas Hellström wrote: > >> Jerome Glisse skrev: >> >>> Hi, >>> >>> Thomas i attach a reworked page pool allocator based on Dave works, >>> this one should be ok with ttm cache status tracking. It definitely >>> helps on AGP system, now the bottleneck is in mesa vertex's dma >>> allocation. >>> >>> Cheers, >>> Jerome >>> >>> >> Hi, Jerome! >> In general it looks very good. Some things that need fixing: >> >> 1) We must have a way to hand back pages. I still not quite understand >> how the shrink callbacks work and whether they are applicable. Another >> scheme would be to free, say 1MB when we have at least 2MB available. >> >> 2) We should avoid including AGP headers if AGP is not configured. >> Either reimplement unmap_page_from_agp or map_page_into_agp or move them >> out from the AGP headers. We've hade complaints before from people with >> AGP free systems that the code doesn't compile. >> >> 3) Since we're allocating (and freeing) in batches we should use the >> set_pages_array() interface to avoid a global tlb flush per page. >> >> 4) We could now skip the ttm_tt_populate() in ttm_tt_set_caching, since >> it will always allocate cached pages and then transition them. >> >> > > Okay 4) is bad, what happens (my brain is a bit meltdown so i might be > wrong) : > 1 - bo get allocated tt->state = unpopulated > 2 - bo is mapped few page are faulted tt->state = unpopulated > 3 - bo is cache transitioned but tt->state == unpopulated but > they are page which have been touch by the cpu so we need > to clflush them and transition them, Right. > this never happen if > we don't call ttm_tt_populate and proceed with the remaining > of the cache transitioning functions > Why can't we just skip ttm_tt_populate and proceed with the remaining of the cache transitioning functions? Then all pages currently allocated to the TTM will be transitioned. /Thomas -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/